Stable Crystalline Organic-Inorganic Hybrid Indium Phosphate with Dye Removal and Ractopamine Detection Applications

Microfluidic Biosensor Decorated with an Indium Phosphate Nanointerface for Attomolar Dopamine Detection

Developing functional materials that directly integrate into miniaturized devices for sensing applications is essential for constructing the next-generation point-of-care system. Although crystalline structure materials such as metal organic frameworks are attractive materials exhibiting promising potential for biosensing, their integration into miniaturized devices is limited. Dopamine (DA) is a major neurotransmitter released by dopaminergic neurons and has huge implications in neurodegenerative diseases. Integrated microfluidic biosensors capable of sensitive monitoring of DA from mass-limited samples is thus of significant importance. In this study, we developed and systematically characterized a microfluidic biosensor functionalized with the hybrid material composed of indium phosphate and polyaniline nanointerfaces for DA detection. Under the flowing operation, this biosensor displays a linear dynamic sensing range going from 10-18 to 10-11 M and a limit of detection (LOD) value of 1.83 × 10-19 M. In addition to the high sensitivity, this microfluidic sensor showed good selectivity toward DA and high stability (>1000 cycles). Further, the reliability and practical utility of the microfluidic biosensor were demonstrated using the neuro-2A cells treated with the activator, promoter, and inhibiter. These promising results underscore the importance and potential of microfluidic biosensors integrated with hybrid materials as advanced biosensors systems.

Functionalized Zirconium Organic Frameworks as Fluorescent Probes for the Detection of Tetracyclines in Water and Pork

The overuse of tetracyclines (TCs) in livestock breeding may cause a series of health and environmental problems. It is necessary to develop more accurate, convenient, and rapid sensing methods toward TCs, but it is still very challenging. In this work, three isostructural zirconium organic frameworks (Zr-MOFs) have been investigated as probes for the fluorescent sensing of TCs in water. By varying the functional group at the central benzene core, their sensing performances toward TCs can be modified. Under optimized conditions, the limit of detection can be as low as 0.08 nM in a wide detection range of 0-147 μM with high sensitivity and selectivity. These Zr-MOFs can also be applied in the detection of TCs in real pork samples with satisfying reliabilities and correctness. This work provides a new method for the design and optimization of fluorescent sensors toward TCs.

Uncommon 3D Twofold Interpenetrated Zinc Phosphate Consisting of Inorganic Chains and Mixed Ligands for Highly Efficient Dye Removal Ability Using Its Nanosized Particles

The flexible blocks are the primary building units for constructing crystalline solids with interpenetrating structures. Herein, we reported a novel class of crystalline material with such structural features, which was made of two tetradentate ligands and one-dimensional (1D) rigid chains of zinc phosphate. This is also the first example of transition metal phosphate incorporating a squarate linker. Furthermore, efficient dye removal ability has been presented.

A Cd(II) Luminescent Coordination Grid as a Multiresponsive Fluorescence Sensor for Cr(VI) Oxyanions and Cr(III), Fe(III), and Al(III) in Aqueous Medium

Hydro(solvo)thermal reactions of Cd(NO₃)₂, N-(pyridin-3-ylmethyl)-4-(pyridin-4-yl)-1,8-naphthalimide (NI-mbpy-34), and 5-bromobenzene-1,3-dicarboxylic acid (Br-1,3-H₂bdc) afforded a luminescent coordination polymer, {[Cd(Br-1,3-bdc)(NI-mbpy-34)(H₂O)]∙2H₂O}_n (1). Single-crystal X-ray diffraction analysis showed that 1 features a two-dimensional (2-D) gridlike sql layer with the point symbol of (4⁴·6²), where the Cd(II) center adopts a {CdO₅N₂} pentagonal bipyramidal geometry. Thermogravimetric (TG) analysis confirmed the thermal stability of 1 up to about 340 °C, whereas XRPD patterns proved the maintenance of crystallinity and framework integrity of 1 in CH₂Cl₂, H₂O, CH₃OH, and toluene. Photoluminescence studies indicated that 1 displayed intense blue fluorescence emissions in both solid-state and H₂O suspension-phase. Owing to the good fluorescent properties, 1 could serve as an excellent turn-off fluorescence sensor for selective and sensitive Cr(VI) detection in water, with LOD = 15.15 μM for CrO₄^2- and 14.91 μM for Cr₂O₇^2-, through energy competition absorption mechanism. In addition, 1 could also sensitively detect Cr³⁺, Fe³⁺, and Al³⁺ ions in aqueous medium via fluorescence-enhancement responses, with LOD = 2.81 μM for Cr³⁺, 3.82 μM for Fe³⁺, and 3.37 μM for Al³⁺, mainly through an absorbance-caused enhancement (ACE) mechanism.